Stereoscopic video imaging

ABSTRACT

Systems and methods for viewing stereoscopic video images are disclosed. The systems can include a first video camera configured to generate a first video feed of a subject, and a second video camera configured to generate a second video feed of the subject. The first video feed and the second video feed combined generate a near real-time stereoscopic video image. A tracking module can be associated with the first video camera and the second video camera, and can be configured to cause the first video camera and the second video camera to be directed to a desired convergent point relative to a selected tracking point to maintain stereopsis. The system may further include an array of video cameras, a gesture control module, an image adjustment module, a calibration module, or a 3-D modeling module, for example.

The present application is a continuation application of U.S. patentapplication Ser. No. 14/403,285 filed Nov. 24, 2014, which is a U.S.National Stage Application of PCT/US2013/029042 filed on Mar. 5, 2013,which claimed the benefit of U.S. Provisional Patent Application No.61/654,697, filed on Jun. 1, 2012, each of which is incorporated hereinby reference in its entirety.

BACKGROUND

Significant technological advancements have been made in the practice ofdentistry. These advancements have enabled better patient care as welldecreased anxiety for patients when visiting a dentist.

Many techniques now used by dentists to provide advanced care involvethe ability to see and focus on very small details in a patient's mouth.Glasses with magnification loops are often used by dentists to increasetheir ability to view fine details. The glasses can be expensive andheavy, becoming burdensome for a dentist to wear for long periods oftime. In addition, the magnification loops can cause eye strain andtunnel vision, reducing a dentist's ability to see both the magnifiedarea and the surrounding area simultaneously.

Additionally, to obtain a desired view of the areas within a patient'sintraoral cavity, a dentist often has to lean forward and hunch. Suchposture can cause long term health problems for a dentist. Dentists thatdo not take precautionary measures regarding their posture can havetheir careers cut short or limited by back pain and other associatedback problems. In addition, these injuries can significantly affect adentist's quality of life outside of the dental office.

BRIEF DESCRIPTION OF THE DRAWINGS

Features and advantages of the present disclosure will be apparent fromthe following detailed description, taken in conjunction with theaccompanying drawings, which together illustrate, by way of example,features of the invention.

FIG. 1 a illustrates a block diagram of a system for viewingstereoscopic video images using a pair of cameras selected from aplurality of at least three video cameras in accordance with embodimentsof the present disclosure;

FIG. 1 b illustrates a block diagram of a system for viewingstereoscopic video images using a gesture control module in accordancewith embodiments of the present disclosure;

FIG. 1 c illustrates a block diagram of a system for viewingstereoscopic video images having an image adjustment module inaccordance with embodiments of the present disclosure;

FIG. 1 d illustrates a block diagram of a system for viewingstereoscopic video images having a calibration module in accordance withembodiments of the present disclosure;

FIG. 1 e illustrates a block diagram of a system for viewingstereoscopic video images having a 3-D modeling module in accordancewith embodiments of the present disclosure;

FIG. 1 f illustrates a block diagram of a system for viewingstereoscopic video images with a wireless data link in accordance withembodiments of the present disclosure;

FIG. 1 g illustrates a block diagram of a system for viewingstereoscopic video images with a wireless data link comprising a singletransmitter and receiver in accordance with embodiments of the presentdisclosure;

FIG. 1 h illustrates a block diagram of a system for viewingstereoscopic video images with a single motor used to update a positionof first and second video cameras in accordance with embodiments of thepresent disclosure;

FIG. 2 provides an example illustration of a dental professional using astereoscopic display to view a near real-time stereoscopic video imageof a patient's intraoral cavity in accordance with embodiments of thepresent disclosure; and

FIG. 3 provides an exemplary diagram illustrating angles at which thefirst and second video cameras are directed and changed based on adistance of the video cameras from a selected object to maintainstereopsis of the video image in accordance with an embodiment of thepresent disclosure.

Reference will now be made to the illustrated exemplary embodiments, andspecific language will be used herein to describe the same. It willnevertheless be understood that no limitation of the scope of theinvention is thereby intended.

DETAILED DESCRIPTION

Before the present invention is disclosed and described, it is to beunderstood that this invention is not limited to the particularstructures, process steps, or materials disclosed herein, but isextended to equivalents thereof as would be recognized by thoseordinarily skilled in the relevant arts. It should also be understoodthat terminology employed herein is used for the purpose of describingparticular embodiments only and is not intended to be limiting.

As a preliminary matter, it is noted that much discussion is relatedherein to the dental profession and conducting dental exams andprocedures. However, this is done for exemplary purposes only, as thesystems and methods described herein are also applicable to othermedical professionals that would benefit from high magnificationstereoscopic imaging and tracking of a desired site for surgery orexamination. For example, the systems and methods herein can beespecially useful in imaging locations where movement may occur, such aswith minimally invasive surgeries when a patient is awake and moving orwith examination of sites of interest of an alert patient. Additionally,the systems and methods of the present disclosure can also be applicableto viewing and tracking in the manner described herein that is outsideof the medical professions generally, e.g., research, teaching,microbiology, electronics, jewel cutting, watch repair, etc.

With this in mind, an initial overview of technology embodiments isprovided below and then specific technology embodiments are described infurther detail thereafter. This initial description is intended toprovide a basic understanding the technology, but is not intended toidentify all features of the technology, nor is it intended to limit thescope of the claimed subject matter.

A dentist's ability to view a patient's intraoral cavity in detail isvaluable for proper diagnosis of dental issues and performance of dentalwork in general. A magnified view of locations within the intraoralcavity can enable a dentist to adequately provide the advanced andcomplex solutions that are now available to patients. However, a typicalsolution to obtain a magnified view is through the use of glasses withone or more magnification loops. The use of magnification loops canstrain a dentist's eyes and increase drowsiness. In addition, a dentistmay need to lean forward and/or slouch in order to obtain a desiredviewing angle inside of a patient's mouth. Over long periods of time,this can cause problems with posture, back pain, and debilitatingphysical damage to a dentist's back. Back pain and injury can reduce thelength of the dentist's career and negatively affect the quality of hisor her life outside of the dentist's office.

In accordance with embodiments of the present disclosure, systems andmethods for viewing stereoscopic video images are disclosed. The systemsand methods, in one example, enable a dentist to obtain a desired viewof a patient's intraoral cavity while reducing eye strain and enablingthe dentist to maintain a proper posture. It is noted that in otherfields, such as medicine, electronics, teaching, microbiology, or anyother field where high magnification stereoscopic vision may be useful,the systems and methods of the present disclosure are equallyapplicable. Thus, as mentioned discussion of dentistry is for exemplarypurposes only and is not considered limiting except as specifically setforth in the claims.

That being said, in order to provide a desired level of care topatients, a hygienist, dentist, oral surgeon, or other type of dentalprofessional should be able to delicately and accurately move dentaltools in a desired direction. Typically, two dimensional images can makeit challenging to accurately move dental equipment within a patient'sintraoral cavity. The use of a stereoscopic image enables stereopsis tobe maintained, thereby allowing a medical professional to perceivedepth, enabling dental equipment to be accurately moved in a desireddirection while viewing the stereoscopic image. As used herein, the term“stereopsis” refers to the process in visual perception leading to thesensation of depth from viewing two optically separated projections ofthe world projected onto a person's eyes, respectively. This can bethrough the use of a head mountable pair of video screens, each with adifferent optical projection, or though optical separation of the twooptical projections on a single video screen, as will be describedhereinafter in greater detail.

In addition, the systems and methods disclosed herein enable multiplepersons viewing the stereoscopic video image to view a selected areafrom the same perspective. For instance, a dentist and a dentalassistant can each view the same stereoscopic video image of a locationsuch as a tooth or an area around a tooth in a patient's mouth. Thecapability for both the dentist and the dental assistant to view astereoscopic video image of the area from the same perspective cansignificantly enhance the ability of the dental assistant to assist thedentist as needed. Moreover, the image may also be viewed by additionalpersons such as the patient or dental school students. The ability ofthe patient to view the same image as the dentist can enable the dentistto better educate the patient as to the condition of his or her teeth,and the procedures that will be conducted. Viewing the stereoscopicimage can significantly enhance student's ability to learn andunderstand the teachings of their instructor from his or her viewpoint.

In accordance with one embodiment of the present disclosure, a systemfor viewing stereoscopic video images can comprise a plurality of videocameras including at least three spatially separated video cameras and atracking module associated with the plurality of video cameras. Theplurality of video cameras can be adapted so that multiple pairs ofvideo cameras are capable of generating a near real-time stereoscopicvideo image, each of the multiple pairs comprising a first video cameraconfigured to generate a first video feed of the subject and a secondvideo camera configured to generate a second video feed of the subject.The tracking module can be configured to cause the first video cameraand the second video camera to be directed to a desired convergent pointrelative to a selected tracking point to maintain stereopsis.

In another example, a system for viewing stereoscopic video images cancomprise an array of video cameras configured for providing video camerafeeds. An image processing module can be configured to i) receive videocamera feeds from the array, ii) geometrically transform one or more ofthe video camera feeds to create a virtual camera feed; and iii)generate a stereoscopic video image from at least two camera feeds. Inthis example, at least one of the two camera feeds can be the virtualcamera feed, and the at least two camera feeds can be directed to aconvergent point. The system also includes a tracking module associatedwith the array, and the tracking module can be configured to follow atracking point relative to the convergent point in order to maintainstereopsis.

In other examples, systems for viewing stereoscopic video images cancomprise a first video camera configured to generate a first video feedof a subject and a second video camera configured to generate a secondvideo feed of the subject, wherein the first video feed and the secondvideo feed combine to generate a near real-time stereoscopic videoimage. These systems can further comprise a tracking module associatedwith the first video camera and the second video camera. The trackingmodule can be configured to cause the first video camera and the secondvideo camera to be directed to a desired convergent point relative to aselected tracking point to maintain stereopsis.

In one specific example, a gesture control module can be associated withthe system, wherein the system responds based on movement of a user. Thegesture control module can include a sensor that senses movement of theuser, for example. In another independent example, an image adjustmentmodule can be configured to selectively modify an image received by thefirst video camera and the second video camera, thereby providing aviewable image having at least one adjusted visual property adapted forenhanced diagnostic or treatment visualization. In yet another specificexample, a calibration module can be configured to calibrate and adjusthorizontal alignment of the first video feed and the second video feed.In still another independent example, a 3-D modeling module can beconfigured to convert the stereoscopic video image into a 3-D model orconstruct.

Turning now to the FIGS., various embodiments of systems 100 for viewingstereoscopic video images are disclosed, as provided in further detailin the example illustrations of FIGS. 1 a-h . There are severalcommonalities between each of these embodiments, including the trackingmodule 108, the first video camera 102 a, the second video camera 102 b,motors 112, and the stereoscopic display 106. Other modules or cameraconfigurations are described in more specific detail with respect tocertain embodiments of the present disclosure. Thus, some features willbe discussed generally with respect to FIGS. 1 a-h , and others will bediscussed specifically with respect to a particular FIG. That beingstated, any combination of features described herein can be practiced inaccordance with examples of the present disclosure.

With specific reference to FIG. 1 a , the system 100 comprises aplurality of video cameras 102 a-d that are spatially separated from oneanother. The plurality of video cameras can be adapted so that multiplepairs of video cameras are capable of generating a near real-timestereoscopic video image, each of the multiple pairs can comprise afirst video camera configured to generate a first video feed of asubject and a second video camera configured to generate a second videofeed of the subject. For example, video camera 102 a and 102 b can bethe first video camera and the second video camera in one situation, andvideo cameras 102 c and 102 d can be the first and second video camerasin a second situation. Furthermore, the video cameras need not bediscrete pairs that are always used together. For example, video camera102 a and video camera 102 c or 102 d can make up a third pair ofcameras, and so forth. Regardless of which two cameras are selected foruse, in a dental environment, for example, the first video camera can bedirected toward the subject to create a first video feed of a patient'sintraoral cavity, and a second video camera can be spaced appropriatelyat a selected distance from the first video camera to create stereopsis.It is noted that the multiple pairs of video cameras can be spatiallyseparated at a pupillary distance from one another, or can be positionedso that they are not necessarily a pupillary distance from one another,e.g., at a simulated pupillary distance with appropriate angles that areoptically aligned with the pupillary distance, or spaced out of opticalalignment with the pupillary distance with some signal correction beingtypical.

The plurality of video cameras can be positioned in a one-dimensionalarray, such as in a straight line, e.g., 3, 4, 5, . . . 25 videocameras, etc., or an a two-dimensional array, e.g., in an arrangementconfigured along an x- and y-axis, e.g., 3×3, 5×5, 4×5, 10×10, 20×20cameras, and so forth. Thus, in either embodiment, any two adjacentvideo cameras can be used as the first video camera and the second videocamera. Alternatively, any two video cameras that may not be adjacent toone another might also be used to provide the stereoscopic image.Selection of which two video cameras to use can be based on manualselection (such as by positive gesture control, or selection ofappropriate buttons, switches, or other interface controls), or can beautomatic based on movement of a user, e.g., a dental professional, or asubject, e.g., patient.

In another related example regarding the array of cameras, any of themultiple cameras 102 a-d (or typically many more video cameras arrangedin an array) can likewise be used to generate a virtual perspective thatcan arise from the placement of a static array of cameras in aparticular orientation in the Cartesian space. For example, the variousvideo cameras can be positioned so that they are known relative to oneother and relative to a user or subject of the system. The position ofthe user or subject within the system can also be known via trackingmethods described herein, or as otherwise known in the art, via hardware(e.g., Polhemus' magnetic tracking or other tracking systems or modules)or via software.

In such a system, camera feeds are taken into an image processing module120 and geometrical transformations can be performed on one or morecamera feeds to create virtual camera feeds that present newperspectives, i.e. perspectives other than those generated directly fromthe camera feeds per se. These virtual camera feeds are then multiplexedto a stereoscopic or 3-D signal for a stereoscopic display or sent to ahead mounted display (e.g., right eye, left eye), to create astereoscopic video. Hardware and software packages, including some stateof the art packages, can be used or modified for this purpose. Forexample, NVIDIA has a video pipeline that allows users to take inmultiple camera feeds, perform mathematical operations on them, and thenoutput video feeds that have been transformed geometrically to createvirtual perspectives that are an interpolation of actual video feeds.These video signals are typically in the Serial Digital Interface (SDI)format. Likewise, software used to perform such transformations isavailable as open source. OpenCV, OpenGL and CUDA, which can be used tomanipulate the video feed. In order to create stereopsis, the imagesdesigned for the left and right eye or optically separated video feed toa single screen, whether virtual or real images are displayed, aretypically separated by a pupillary distance or simulated pupillarydistance, though this is not required. It is noted that the imageprocessing module shown in this example for purposes of generatingvirtual camera feeds. However, any other type of image processing thatmay be beneficial for use in this embodiment or any other embodimentherein that would benefit from image processing can also include animage processing module.

In either of these two embodiments, i.e. pairing of various videocameras from a plurality of camera feeds or generating a virtual imageusing an array of cameras, there are many ways of controlling theselection of video cameras or generation of virtual images. User orsubject movement, for example, may be used to control these systems, andmay include movement of a user's head or eyes, or movement of asubject's intraoral cavity. The automatic selection can be configured toprovide a desired image based on a position of the dental professionalor patient relative to one another. For instance, when the dentalprofessional changes the angle at which he or she is viewing thepatient, cameras in the array can be selected and/or moved to provide animage based on the viewing angle of the dental professional.

In further detail regarding gesture controls, FIG. 1 b sets for agesture control module 110 that is associated with the systems 100 ofthe present disclosure. Though some details regarding gesture controlswere described previously with respect to selection of a pair of camerasfrom a plurality of at least three video cameras, gesture controls arealso applicable to embodiments where only two video cameras are presentas well. More specifically, the gesture control module can include asensor that senses movement of a user, such as a dental professional,and responds based on that movement. Gestures can either be deliberateto cause an action, or can be incidental to typical movements of theuser. A deliberate gesture might include hand or arm gesture, ordeliberate movement of an instrument held in the hand of the user. Avoice gesture, e.g., voice commands, is also an example of a deliberategesture.

Alternatively, the system of the present disclosure can also controlledby incidental movements by the user, such as causing the tracking moduleto follow a tracking point based on eye or head movement of the user.When tracking eye movement, sensors can be directed to or present nearthe user's eyes, such as a camera directed to the user's eyes or sensorson a pair of glasses used to optically separate a stereoscopic image ona video screen or on head mountable stereoscopic display. Thus, thecamera or sensors can be used to detect a movement of the user's eyes,and/or the cameras in the array can be selected and/or moved to providean image based on the viewing angle of the user's (i.e. dentalprofessional's) eyes. In either case, gestures can be used to move atracking point, adjust light settings, modify a level of magnification(using a zoom module), or any other adjustment that may be desirable foruse with the systems of the present disclosure.

Turning now to the system 100 of FIG. 1 c , in addition to the trackingmodule 108, motor 112, first video camera 102 a, second video camera 102b, and stereoscopic display 106 set forth in this embodiment, each ofwhich will be described in further detail hereinafter, an imageadjustment module 114 is also included. The image adjustment module canbe configured to selectively modify images received by a first videocamera and a second video camera and provide a viewable image having atleast one adjusted visual property adapted for enhanced diagnostic ortreatment visualization.

For example, the adjusted visual property may include enhancement orshifting of a specific optical frequency band for enhanced resolvingpower of a dental professional to view the specific optical frequencyband. Specifically, a color or group of colors can be enhanced orshifted in viewable color, such as for diagnosing or treating cancers orlesions in the mouth, diagnosing or treating soft tissue anomalies(e.g., gums, tongue, cheek, etc.), diagnosing or treating teeth (e.g.,cavities), etc. To provide a more specific example infrared, green,amber, white, violet, ultraviolet, or a combination of these lightfrequencies can be used to enhance the detection of cancerous tissue.The image detected by the cameras can be so modified such that thecoloration is enhanced using the image adjustment module for diagnosisor treatment purposes.

In another example, there are circumstances where specific lightingprofiles are used (or avoided) in conjunction with some materials, e.g.,amber light or UV light. For instance, UV lighting may be used to curecertain materials. Amber lighting may be used when curing of materialsis not desired. Thus, the system can be adapted for use under thatspecific lighting profile, and the adjusted visible property can be todecrease the artificial coloration of the viewable image on thestereoscopic display, making it appear more natural to the user, e.g.,amber light environment where the amber light is minimized and otherlight is enhanced that may be only minimally present.

In still another example, the system can be adapted for use in highlysaturating light, and the adjusted visible property can be to decreasethe white or other saturation of the viewable image. This may be usefulwhen there is a desire to more accurately visualize a certain color,such as when matching off-white coloration for cosmetic orreconstructive dentistry. In yet another example, there may beadvantages in utilizing the system to detect and shift otherwiseinvisible light into the visible spectrum, e.g., ultraviolet light suchas 405 nm light. If this is the case, sensors on the video cameras, suchas charged couple device (CCD) sensors or complementary metal oxidesemiconductor (CMOS) sensors can be selected that are sensitive toultraviolet light. In one embodiment, multiple sensors may be providedin a single camera, with different sensors tuned to different parts ofthe light spectrum. For instance, one sensor may be configured to detectwavelengths from infrared to blue, while another sensor may beconfigured to detect ultraviolet wavelengths. The appropriate sensor ineach camera can be selected based on the color (i.e. wavelength) oflight being imaged by the cameras.

In related embodiments, the adjusted visual property can be furtherenhanced by the presence of a colorant. By selecting certain colorants(pigments or dyes) for use in the intraoral cavity, certain materials orconditions can be amplified. This, coupled with the ability to adjust avisual property of the colorant can provide a combination that wouldmake certain dental tasks easier for the dental professional tovisualize. For example, a dye or pigment may be used, and the videoimage can be used to enhance or even shift coloration of the dye orpigment, making it more easily viewable. In one specific example,certain fluorescent dyes or pigments can be used for determining thepresence of a dental material, such as a bonding cement, and thecoloration can help the dental professional determine whether it isproperly cured. In another example, a colorant can be used to attach tocertain types of dental conditions, such as cavities, lesions, cancers,or the like, to assist the dentist in diagnosing or treating a dentalcondition. The digital imaging sensors in the cameras and/or the outputsignals of the digital imaging sensors can be configured to enhance theview of the colorant on the stereoscopic display 106.

FIG. 1 d sets forth a system 100 that includes a calibration module 116,in addition to the tracking module 108, motor 112, first video camera102 a, second video camera 102 b, and stereoscopic display 106. Thecalibration module can be configured to calibrate and adjust horizontalalignment of a first video feed and a second video feed so that thepixels from the first video camera are aligned with the pixels of thesecond video camera. When the stereoscopic display is a head mountablestereoscopic display including a right video display and a left videodisplay, proper alignment of the two images can be calibrated to theeyes of the user horizontally so that the image appears as natural aspossible. The more unnatural an image appears, the more eye strain thatcan result. Horizontal alignment can also provide a clearer image whenviewing the near real-time stereoscopic video image on a screen (with orwithout the assistance of viewing glasses). When the pixels are properlyaligned, the image appears more natural and sharper than might be thecase when the pixels are misaligned even slightly. Additionalcalibration can also be used to adjust the vertical alignment of thefirst video camera and the second video camera to a desired angle toprovide stereopsis. In either case, whether the calibration module isused to for vertical or horizontal alignment, the alignment can beconfigured to be maintained or recalibrated when something changes,e.g., after pan or tilt movements of the first video camera or thesecond video camera, the selection of different video cameras to pair inthe array, and so forth. These movements may cause minor misalignmentthat can be readjusted as the misalignment occurs. The calibrationmodule can be configured to allow manual adjustment and/or automaticadjustment of horizontal and/or vertical alignment of the camera pair.

Other uses for calibration can occur when the system is first set up, orwhen multiple users are using the same equipment. In one example, thecalibration module can provide for calibration with multiple users.Thus, the system can be calibrated for a first user in a first mode anda second user in a second mode, and so forth. For example, a focus ofeach camera in the camera pair can be adjusted to compensate for visiondifferences. The system can be configured to switch between the firstmode and the second mode automatically or manually based on whether thefirst user or the second user is using the system.

FIG. 1 e sets forth a system 100 that includes a 3-D modeling module118, in addition to the tracking module 108, motor 112, first videocamera 102 a, second video camera 102 b, and stereoscopic display 106.The 3-D modeling module can be configured to convert the stereoscopicvideo image into a 3-D model or construct. This module can output one ormore frame of the stereoscopic video image to a modeling device, such asa 3-D printer, tooth impression modeling device, or a 3-D CAD drawingthat can be further used to prepare a 3-D model. Any 3-D modelingtechnique can be used, as is known in the art, once the stereoscopicimage is outputted to the appropriate technology for generating a 3-Dmodel or construct.

In the embodiments described above in FIGS. 1 a-e , the first video feedfrom the first video camera 102 a and the second video feed from thesecond video camera 102 b can be communicated to the stereoscopic videodisplay 106 through wired communication cables, such as a digital visualinterface (DVI) cable, a high-definition multimedia interface (HDMI)cable, component cables, and so forth. Alternatively, the informationfrom the first video feed and the second video feed can be communicatedwirelessly to the stereoscopic video display. For instance, FIG. 1 fshows a system 100 that provides a wireless 142 data link between thevideo display and each of the first video camera and the second videocamera. In yet another example, as displayed in FIG. 1 g , the first andsecond video feeds are communicated via a wired connection to a singletransmitter 146. The transmitter can wirelessly 142 communicate thefirst and second video feeds from the first and second video cameras,respectively, to the video display. A wireless receiver 144 at the videodisplay can be used to receive the first and second video feeds from thetransmitter and communicate the video feeds to the video display.

Various standards which have been developed or are currently beingdeveloped to wirelessly communicate video feeds include the WirelessHDstandard, the Wireless Gigabit Alliance (WiGig), the Wireless HomeDigital Interface (WHDI), the Institute of Electronics and ElectricalEngineers (IEEE) 802.15 standard, and the standards developed usingultrawideband (UWB) communication protocols. In another example, theIEEE 802.11 standard may be used to transmit the signal(s) from thevideo cameras 102, 104 to the stereoscopic display 106. One or morewireless standards that enable the video feed information from the firstand second video feeds to be transmitted to the stereoscopic videodisplay for display in near-real time can be used to eliminate the useof wires and free the user to move about more freely. This can beespecially useful when the stereoscopic video display is head mountable,though it is also desirable in any of the video display embodimentsdescribed herein.

In further detail with respect to FIGS. 1 a-g , it is noted that eachcamera that is shown can include an individual motor associatedtherewith to control a direction and/or focus of the camera. FIG. 1 hprovides an example illustration of another embodiment, wherein a singlemotor 112 is used to update a position of the first and second videocameras 102 a, 102 b together. The single motor can be mechanicallycoupled to the first and second video cameras. For example, the motormay be connected through a series of gears and/or screws that allow themotor to be used to change an angle in which the video cameras aredirected. Other types of mechanical couplings can also be used, as canbe appreciated. Any type of mechanical coupling that enables the motorto update a direction in which one or both of the first and second videocameras are pointed is considered to be within the scope of thisembodiment.

In each of the embodiments described in FIGS. 1 a-h , as mentioned,there are several details regarding various elements of the FIGS. thathave some commonality. Some of these features will be discussed togetherhereinafter. For example, regarding the spacing of the first videocamera 102 a and the second video camera 102 b, the cameras can behorizontally spaced to simulate the spacing between a person's eyes inorder to produce a first video feed and a second video feed that iscombinable to generate a natural stereoscopic image, e.g., the image canbe displayed to simulate a person's vision from his or her left eye andright eye. This spacing can be referred to as pupillary distance. Atypical pupillary distance is from about 50 millimeters (mm) to about 75mm. Alternatively, the cameras may be spaced a different (typicallygreater) distance apart, but can still be optically or digitally alignedto provide approximately the pupillary distance. In other embodimentswhere the distance between the cameras is not the pupillary distance orat least does not optically simulate the pupillary distance, some signalprocessing may be desirable to otherwise compensate for more unnaturalcamera convergence angles and distances therebetween.

The systems can further comprise a stereoscopic video display 106, asshown in FIGS. 1 a-h . In one embodiment, the stereoscopic display canbe a head mountable stereoscopic display with a right video displayviewable by a person's right eye and a left video display viewable by aperson's left eye. By displaying the first and second video feeds in theleft and right video displays, a near real-time stereoscopic video imagecan be created. Alternatively, the stereoscopic display can be a singlevideo screen wherein the first video feed and the second video feed areoptically separated, e.g., shutter separation, polarization separation,color separation, etc. The stereoscopic display can be configured toallow a user to view the stereoscopic image with or without an externalviewing device such as glasses. In one embodiment, a pair of appropriateglasses that work with shutter separation, polarization separation,color separation, or the like, can be used to allow the screen to beviewed in three-dimensions. Still further, the video display cancomprise multiple video displays for multiple users to view the nearreal-time stereoscopic video image, such as the dental assistant and/orthe patient.

The stereoscopic video image provides a visual perception leading to thesensation of depth from the two slightly different video imagesprojected onto the retinas of the person's two eyes. This visualperception leading to the sensation of depth is referred to asstereopsis. No additional video or computer processing of the first andsecond video images may be needed when using the head mountablestereoscopic display or the other optical separation technologydescribed above. The sensation of depth is created due to the differingprojections of the first and second cameras that are separated by, forexample, a pupillary distance or simulated pupillary distance. Thatbeing stated, there are instances where the cameras may be further apartor angled in a manner that does not correspond to a typical pupillarydistance, and in those arrangements, the near real-time stereoscopicvideo image can thus be corrected to provide a simulated pupillarydistance based on the images received from two or more cameras in thecamera array, as previously discussed.

The ability to perceive depth can be valuable to a dentist that isworking with a patient. Proper depth perception enables the dentist tomake small, but critical movements when performing dentistry.Previously, the lack of ability to display depth perception has limitedthe use of cameras and display screens in the practice of dentistry.With the use of two separate cameras that are configured to provide adisplay with stereopsis, a dentist can view the resulting stereoscopicdisplay that provides the sensation of depth, thereby enabling thedentist to maintain substantially the same hand-eye coordination thatthe dentist has learned during his or her practice using loops or othermagnification systems.

Returning to FIGS. 1 a-h , the various systems 100 can also include atracking module 108 that is in communication with the first video camera102 a and the second video camera 102 b (or the plurality of videocameras as described specifically in FIG. 1 a ). The tracking module canbe configured to cause the first video camera and the second videocamera to be directed to a desired convergent point relative to aselected tracking point.

The tracking point can be a selected location on or about the patient'sbody that enables the cameras 102 a, 102 b to be redirected relative tothe motion of the tracking point. For instance, the tracking point maybe at a location on the patient's head. When the patient moves his orher head, the cameras can move with the patient so that the image on thedisplay screen is not substantially changed due to movements of thepatient. Alternatively, the tracking point may be located at or about adental patient's intraoral cavity. For instance, the tracking point maybe located on a tooth, a dental tool, or on a dental retractor locatedin or about the patient's intraoral cavity. Further, as discussed withrespect to certain examples herein, the tracking point can be associatedwith the user, e.g., the dental professional, and movement of the usercan relate directly to the tracking function.

The tracking point can be provided by any type of device, object, orsignal that enables the movement of the patient to be tracked relativeto the position of the cameras. For instance, tracking may beaccomplished using radio frequency triangulation. Multiple trackingtransceivers can be located on or about the patient. A marker, such as atool, can also include a transceiver. The location of the tool relativeto the location of the markers can be calculated based on the timing ofthe arrival of tracker signals transmitted from the tool transceiver atthe tracking transceivers. The location of the tool transceiver can becalculated using trigonometry, for example.

In another embodiment, the tracking point may be an optically trackablemarker such as a reflective dot or an optical dot formed using adifferent colored light or an infrared light source. The light sourcesfor the colored light or the infrared light may be one or more lightemitting diodes or lasers. The tracking module can include imagerecognition software that enables the cameras to be substantiallydirected relative to the optically trackable marker. Alternatively, aninfrared receiver can be used to track a location of an infrared opticaldot.

In another embodiment, the tracking module 108 can include imagerecognition software may be used that can recognize a location orfeature, such as a person's nostrils, eyes, or other distinctcharacteristics. As the person's selected feature moves, the position ofthe camera can be adjusted to maintain the stereoscopic video image of aselected area within the person's intraoral cavity. The ability toadjust a direction of the video cameras relative to movement of thepatient can enable the video cameras to provide a relatively high amountof magnification of a desired location within the intraoral cavity. Theimage recognition software can be programmed to recognize patterns. Forexample, software that includes facial recognition technology can beused with the systems of the present disclosure that is similar to thatwide used with state of the art point and shoot digital cameras, e.g.,boxes in digital display screens appear around faces to inform the userthat a face of a subject has been recognized for focus or other purpose.

Accordingly, the systems of the present disclosure can also include anoptional zooming module 110, shown in FIG. 1 f . Though the zoomingmodule is shown only in FIG. 1 f , it is understood that the zoomingmodule can be used in any of the embodiments described herein. Thezooming module can be in communication with the first video camera 102 aand the second video camera 102 b. The zooming module can be configuredto provide a desired magnification of the near real-time stereoscopicvideo image. As previously discussed, the ability to view a desiredlocation with a selected magnification provides a significant advantageto a dentist to conduct complex and detailed procedures. Dentiststypically use glasses with magnification loops to magnify images in theorder of about 4 times. However, in accordance with embodiments of thepresent disclosure, zooming ranges are only limited by the zooming rangeof the first and second video camera.

In one specific embodiment, the video cameras 102 a, 102 b can beconfigured to provide a magnification from one time to over 20 times astandard image, or more. The magnification may be achieved eitherthrough the use of an optical magnification, a digital zoom, or acombination of the two. The stereoscopic display can provide a clear,focused image of the desired location within the patient's intraoralcavity at a high magnification. The video cameras can be set atsubstantially the same magnification to enable the visual perceptionleading to a sensation of depth to be maintained. In addition, the rateat which the cameras change magnification can be substantially the sameto maintain stereopsis of the stereoscopic video image as the image iszoomed in and out using the zooming module to communicate with the firstand second video cameras.

In another embodiment, the first and second video cameras 102 a, 102 band the stereoscopic display 106 can be configured to display arelatively high resolution. For instance, the cameras and display can beconfigured to provide a 720P progressive video display with 1280 by 720pixels (width by height), a 1080i interlaced video display with1920×1080 pixels, or a 1080p progressive video display with 1920×1080pixels. As processing power and digital memory continue to exponentiallyincrease in accordance with Moore's Law, the cameras and display mayprovide an even higher resolution, such as 4320P progressive videodisplay with 7680×4320 pixels. With higher resolution, an image can bemagnified using software (digital zoom) to provide a digitalmagnification without substantially reducing the image quality. Thus,software alone may be used to provide a desired magnification level ofthe real-time stereoscopic video image.

FIG. 2 provides an example illustration of a dentist 232 using a headmountable stereoscopic display 206 to view a near real-time stereoscopicimage of a patient's intraoral cavity in accordance with one embodimentof the present disclosure. The first video camera 202 a and the secondvideo camera 202 b can be mounted on a fixture 242 above the patient234.

A light 236, such as a dental light source, can be provided toilluminate the patient's intraoral cavity. The light can providesufficient illumination to enable the first video camera 202 and thesecond video camera 204 to zoom to a desired magnification level whilemaintaining a selected depth of field for the near real-timestereoscopic video image. The depth of field can be selected to enablethe dentist to have a clear, focused view of all of the desiredlocations within the patient's intraoral cavity. The aperture of thefirst and second video cameras may change when the magnificationprovided by the video cameras is increased. Alternatively, the lightsource may be sufficiently bright that no change in aperture is needed.The light may also be provided to generate various lighting profilesthat would be useful with the image adjustment module previouslydescribed in relation to FIG. 1 c.

The depth of field of the first and second video cameras 202 a, 202 bmay be greater than a length of the patient's intraoral cavity. Forexample, if the depth of field of the first and second video cameras istwice the depth of a typical patient's intraoral cavity, then the firstand second video cameras can be focused on the patient's lip whilemaintaining a clear focus to the back of the patient's mouth, assumingthat the depth of field of the cameras is centered.

In one embodiment, the head mountable stereoscopic video display 206 canbe configured to provide a split field of view, with a bottom portion ofthe glasses providing separate high definition displays for the left andright eyes, and above the glasses, the dentist can view the environmentunencumbered. Alternatively, the glasses can be configured in a splitview where the bottom half provides the video image, and the top half ofthe glasses is substantially transparent to enable an operator to viewboth natural surroundings while wearing the head mountable stereoscopicdisplay. This can be especially useful as the dentist is using a highmagnification level while working on the patient's mouth and can movequickly to no magnification when viewing the surrounding environment.

Alternatively, a video display other than the head mountablestereoscopic video display can be positioned to display the nearreal-time stereoscopic video image as well. For instance, a largetelevision screen can be configured to show three dimensional images.The placement is based on a desired application, but in one embodiment,it may be placed behind the patient 234 in a position that enables thedentist 232 to view the video image. It can also be placed for thepatient to view, or for students to view for learning in an educationalenvironment, for example. The video display can be configured to enableviewers to view the stereoscopic display 246 as a three dimensionalimage, either with or without the assistance of eyewear.

For instance, in one embodiment the first and second video feeds can bedisplayed on a single display screen 246, with the respective videofeeds being optically separated. Technologies for optical separationinclude shutter separation, polarization separation, and colorseparation. In one embodiment, a viewer or user, such as a dentist, canwear viewing glasses to view the separate images with stereopsis anddepth perception. In other embodiments, multiple stereoscopic videos canbe displayed, such as on multiple television screens. For instance, thestereoscopic image can be simultaneously displayed on a televisionscreen, a projection display, and a head mountable stereoscopic videodisplay.

Certain types of viewing glasses, such as LCD glasses using shutterseparation, may be synchronized with the display screen to enable theviewer to view the optically separated near real-time stereoscopic videoimage. The optical separation of the video feeds provides a visualperception leading to the sensation of depth from the two slightlydifferent video images projected onto the retinas of the two eyes,respectively, to create stereopsis. As previously discussed, thesensation of depth enables the dentist to maintain substantially thesame hand-eye coordination that the dentist has learned during his orher practice as a dentist.

The stereoscopic video display 206 can also be used to view informationpertaining to the patient. For instance, x-rays can be digitized andviewed on the video display. A patient's chart information can also bedisplayed. This can enable the dentist to quickly come up to speed onthe patient's status. The dentist can also make comparisons betweenprevious images and information contained in the patient's chart and thepatient's current status. The images can also be used to educate thepatient, dental assistants, and so forth.

In one embodiment, the fixture 242 can be hingeably mounted or otherwiseheight adjustable. The distance of the video cameras to the patient canbe varied as desired. For instance, the video cameras may be positionedat a distance from about 5 inches to about 96 inches above the patient'sintraoral cavity. As the distance between the video cameras and thepatient changes, the angle at which the first video camera and thesecond video camera are directed relative to one another can be adjustedto maintain stereopsis of the near real-time stereoscopic video image.

FIG. 3 provides an exemplary diagram illustrating how the angles of thefirst and second video cameras 302 a, 302 b are related to a distancefrom an object. It should be noted that the illustration is not drawn toscale. The cameras can be separated by a selected distance, such as apupillary distance, as previously discussed. In one embodiment, distanced₁ can be substantially equal to distance d₂. In this example, d₁=d₂=30mm. However, the actual distance may vary based on system needs, e.g.,d₁+d₂=a value in the range of about 50 mm to 75 mm.

In order to view a selected object 320 or area, such as a tooth in thisexample, the first video camera 302 a is directed to the object at anangle θ₁ with respect to a normal. The second video camera 302 b can bedirected to the object at an angle θ₂ with respect to the normal. Whenthe object is centered between the cameras 302 a, 302 b then θ₁ issubstantially equal to θ₂, though this is not necessarily required.

The first video camera 302 a can create a video image of a first plane310, based on the angle θ₁. The second video camera 302 b can create avideo image of a second plane 312 based on the angle θ₂. The first andsecond planes 310, 312 cross at a location referred to as a convergentpoint 316. In one embodiment, the convergent point can be selected to bepositioned at approximately the location of the object 320.Alternatively, the convergent point may be selected to be within thedepth of field of the cameras. When the image is magnified by zoomingthe first and second cameras, then the convergent point can be selectedsuch that it is within the final, magnified video image.

As the distance d₃ between the cameras 302 a, 302 b and the object 320changes, the angles θ₁ and θ₂ can be adjusted such that the convergentpoint is maintained at approximately the same location. The distance ofd₃ may change when a position of the fixture 242 of FIG. 2 is adjustedrelative to the patient 234. The distance of d₃ may also change when thepatient moves.

As previously discussed, a tracking point can be used to track movementsof the patient. In one embodiment, the convergent point can be separatefrom the tracking point. For instance, the tracking point may be anoptical marker on a patient's forehead and the convergent point can bethe focus point on a patient's tooth. The convergent point can becorrelated with the tracking point such that when the tracking pointmoves a certain amount in at least one of the x, y, and z axes, theconvergent point can be moved approximately the same distance.Alternatively, the tracking point may be substantially equal to theconvergent point. This allows the video feeds of a selected locationthat are created by the first and second video cameras 302 a, 302 b tobe maintained even when the patient moves, thereby enabling the dentistto maintain a view of the near real-time stereoscopic video image of theselected location.

Returning now to FIGS. 1 a-h for purposes of describing actuation of thevideo cameras, the direction in which the first and second video cameras102 a, 102 b are positioned can be updated using at least one electricmotor 112 that is mechanically coupled to each video camera. Forinstance, a single motor may be used to cause an angle of a video camerato be changed along a first axis, such as rotating the video camera. Asecond motor may be used to allow the video camera angle to be adjustedalong a second axis. In one embodiment, two motors are sufficient toallow each video camera to be adjusted along an x and y axis to directeach video camera in a desired direction. However, a third motor may beused to allow the video camera's position to be adjusted along a thirdaxis. The three motors can allow each video camera's position to beredirected along an x, y, and z axis to be directed in substantially anydirection.

The at least one motor 112 can communicate with the tracking module 108to update the position of the first and second video cameras. In oneembodiment, a user can manually actuate the position of the first andsecond video cameras 102 a, 102 b through the use of a softwareinterface that is in communication with the at least one motor 112.

Once the video cameras 102 a, 102 b are set in a desired direction,enabling the user to view a selected area, such as a patient's tooth,the location can be set as the convergent point. As previouslydiscussed, the convergent point is associated with a selected trackingpoint. The position of the tracking point can be selected such thatthere is about a one to one movement of the tracking point in relationto the convergent point. For instance, an optical marker may be placedon a patient's forehead or somewhere else that is convenient for a givenapplication. When the patient moves his or her head, the change inposition of the forehead is generally substantially similar as thechange in position of the patient's tooth (barring some sort ofunnatural twisting movement that would be less likely while sitting in adentist chair). Thus, when the tracking point moves, the position of thecameras can be updated relative to the movement of the tracking point toenable the convergent point to be maintained over the same selectedarea, such as the patient's tooth. The dentist may use an insert, suchas a retractor inserted in the patient's oral cavity, so that the angleof opening of the jaw remains substantially unchanged. In oneembodiment, when using a retractor, the tracking point can be placedthereon, or on another area close to or within the oral cavity, such asa tooth, lip, cheek, nose, chin, etc. In another embodiment, when usinga retractor, such as a cheek retractor, LED or other lighting sourcescan be included on the retractor. Thus, in embodiments of the presentdisclosure where an image adjustment module 114 is used (See FIG. 1 c ),the lighting profile provided by the cheek retractor can be selected forlight enhancement or shifting as previously described.

The position of the first and second video cameras 102 a, 102 b can alsobe affected by physically changing their location relative to a patient.For instance, the cameras may be mounted on a fixture that can berotated, raised and lowered, hingeably moved, or otherwise repositioned,as discussed in FIG. 2 . When the position of the video cameras arechanged by moving the fixture, then the at least one motor 112 can beused to redirect the video cameras to the selected area. In oneembodiment, the position of the fixture can be used in conjunction withthe motors to direct the video cameras in a desired direction. Forinstance, a dentist may position the fixture to provide desired lightingand align the video cameras with a patient's intraoral cavity to allowthe video cameras to be directed to a desired location within theintraoral cavity.

In other related embodiments, several methods for viewing stereoscopicmedical video images are also disclosed. The methods generally includedirecting a first video camera and a second video camera to a selectedarea of a subject to generate a respective first video feed and a secondvideo feed of the selected area, wherein the first video camera isseparated from the second video camera by a selected distance, andwherein the first video camera and the second video camera are eachdirected to a convergent point at or near the selected area to providestereopsis of the selected area. Additional steps include associatingthe convergent point with a selected tracking point; adjusting alocation of the convergent point relative to movement of the selectedtracking point; and displaying the first video feed and the second videofeed on a display system that optically separates the first video feedand the second video feed to create a near real-time stereoscopic videoimage.

This general method can also include additional steps. For example, inone embodiment, the step of selecting the first video camera and thesecond video camera from an array of video cameras can be included. Twocameras of the array can be selected to generate the near real-timestereoscopic image, or a virtual image can be generated using at leastone virtual video feed. In this latter embodiment, the method forviewing stereoscopic video images can comprise obtaining an array ofvideo cameras and generating multiple video camera feeds from multiplevideo cameras of the array. Additional steps include geometricallytransforming at least a plurality of the video feeds to create a virtualcamera feed; tracking a selected tracking point related to a convergentpoint; and creating a near real-time stereoscopic video image. Thestereoscopic video image can comprise at least two camera feeds, and atleast one of the two camera feeds is the virtual camera feed.Furthermore, the at least two camera feeds are typically directed to theconvergent point.

In another example, the method can include the step of modifying thenear real-time stereoscopic image as a result of a gesture controlmotion of a user. In another example, the method can include the step ofselectively modifying a light signal received by the first video cameraand the second video camera, thereby providing a viewable image havingat least one adjusted visual property adapted for enhanced diagnostic ortreatment visualization by a user. Thus, when displaying the nearreal-time stereoscopic video image, the adjusted visual property canprovide the user, e.g., medical or dental professional, with addedinformation for diagnostics or treatment. In another example, the methodcan include a calibration module configured to calibrate and adjusthorizontal alignment of the first video feed and the second video feed.In still another embodiment, the method can include the step ofgenerating a 3-D model from at least one frame of the near real-timestereoscopic video image.

Regarding the step of directing the first video camera and the secondvideo camera to a selected area of a subject to generate a respectivefirst video feed and a second video feed of the selected area, it isnoted that the first video camera can be separated from the second videocamera by a selected distance. In one embodiment, the selected distancecan be a pupillary distance, or alternatively, a different distance maybe selected, as previously discussed, e.g., distances that simulate thepupillary distance by using appropriate angles, or adjusting the imagesusing a processing step. Typically, the first video camera and thesecond video camera are each directed to a convergent point at or nearthe selected area to provide stereopsis of the selected area.

These methods can further comprise associating the convergent point witha selected tracking point on or about a subject. The selected trackingpoint can include an optically trackable marker, as has been discussed.In one embodiment, the optically trackable marker may be positioned on adental retractor located in or about the patient's intraoral cavity.Alternatively, the selected tracking point can include a plurality ofwireless transceivers configured to triangulate a position of theselected tracking point based on the timing of signals received at atransceiver located at the tracking point relative to at least two othertransceivers positioned on or about the patient.

For instance, in one embodiment, a surgical operating room may includefour separate radio frequency transceivers positioned at differentlocations about the operating room. A tracking transceiver can then beplaced on a patient entering the operating room. The trackingtransceiver can send or receive signals from the transceivers located inthe operating room. The timing of the signals between the trackingtransceiver and the four transceivers in the operating room can be usedto determine the position of the tracking transceiver in threedimensions using trigonometry, as can be appreciated. The accuracy ofthe triangulation calculation is based, at least in part, on thefrequency of the transceivers. Higher frequency transceivers haveshorter wavelengths, thereby enabling a more accurate determination ofthe position of the tracking transceiver. Increased accuracy can also beobtained by merely tracking the change in movement. As the trackingtransceiver moves closer to one of the transceivers in the room, andfurther from another, the resulting change in the timing of the signalscan enable a substantially accurate determination of the change inposition of the tracking transceiver.

The methods further comprise adjusting a location of the convergentpoint relative to movement of the selected tracking point. In oneembodiment, the convergent point can be selected as a virtual point thathas an x, y, and z axis distance from the tracking point. When thetracking point is moved then the first video camera and the second videocamera can be redirected to maintain a view of the selected area basedon the change in the x, y, and z axis distance of the tracking point.For instance, once the convergent point has been selected relative tothe tracking point, the tracking point may move 1 inch in each of the x,y, and z axes due to a movement of the patient on which the trackingpoint is located. It can be assumed that the convergent point has alsobeen moved 1 inch in each of the x, y, and z axes and the position ofthe first and second video cameras can be redirected to the adjust thelocation of the convergent point to the new location.

The methods may further include displaying the first video feed and thesecond video feed on a display system that optically separates the firstvideo feed and the second video feed to create a near real-timestereoscopic video image. In one embodiment, the first video feed can bedisplayed on a right video display of a head mountable video display andthe second video feed can be displayed on a left video display of thehead mountable video display. The right and left video displays can beprojected onto a user's right and left eyes, respectively. Thestereoscopic video image provides a visual perception leading to thesensation of depth from the two slightly different video imagesprojected onto the retinas of the two eyes.

Alternatively, the first video feed and the second video feed can bedisplayed on a single display wherein the first video feed and thesecond video feed are optically separated using at least one of shutterseparation, polarization separation, and color separation, as previouslydiscussed. Depending on the type of optical separation used, glasses maybe used to enable a user to separate the image displayed on the singledisplay to the first video feed being directed to the user's right eyeand the second video feed being directed to the user's left eye, or viceversa.

The first video camera and the second video camera can each be zoomed toprovide a desired level of magnification of a selected portion of thenear real-time stereoscopic image. The rate at which the magnificationchanges for each of the first and second video cameras can besubstantially equal to maintain the stereopsis of the stereoscopic videoimage. The final amount of magnification can also be substantially equalfor the same reason. In addition to optically magnifying thestereoscopic video image using the first and second cameras, the videoimage can be further magnified using digital magnification, as can beappreciated.

In discussing the systems and methods of the present disclosure above,is also understood that many of the functional units described hereinhave been labeled as “modules,” in order to more particularly emphasizetheir implementation independence. For example, a module may beimplemented as a hardware circuit comprising custom VLSI circuits orgate arrays, off-the-shelf semiconductors such as logic chips,transistors, or other discrete components. A module may also beimplemented in programmable hardware devices such as field programmablegate arrays, programmable array logic, programmable logic devices, orthe like.

Modules may also be implemented in software for execution by varioustypes of processors. An identified module of executable code may, forinstance, comprise one or more physical or logical blocks of computerinstructions, which may, for instance, be organized as an object,procedure, or function. Nevertheless, the executables of an identifiedmodule need not be physically located together, but may comprisedisparate instructions stored in different locations which, when joinedlogically together, comprise the module and achieve the stated purposefor the module.

Indeed, a module of executable code may be a single instruction, or manyinstructions, and may even be distributed over several different codesegments, among different programs, and across several memory devices.Similarly, operational data may be identified and illustrated hereinwithin modules, and may be embodied in any suitable form and organizedwithin any suitable type of data structure. The operational data may becollected as a single data set, or may be distributed over differentlocations including over different storage devices, and may exist, atleast partially, merely as electronic signals on a system or network.The modules may be passive or active, including agents operable toperform desired functions.

While the forgoing examples are illustrative of the principles of thepresent invention in one or more particular applications, it will beapparent to those of ordinary skill in the art that numerousmodifications in form, usage and details of implementation can be madewithout the exercise of inventive faculty, and without departing fromthe principles and concepts of the invention. Accordingly, it is notintended that the invention be limited, except as by the claims setforth below.

What is claimed is:
 1. A system for generating stereoscopic videoimages, comprising: an array of video cameras comprising multiple pairsof video cameras, wherein a first pair of video cameras include a firstvideo camera to generate a first video feed of an object and a secondvideo camera to generate a second video feed of the object, wherein thefirst video feed and the second video feed provide a stereoscopic videoimage at a convergent point; and a tracking device associated with thearray of video cameras, the tracking device configured to control thefirst pair of video cameras to track a tracking point and to move fromthe first pair of video cameras to a second pair of video cameras totrack the tracking point and maintain stereopsis at the convergent pointof pairs of video cameras while generating the first video feed and thesecond video feed.
 2. The system of claim 1, wherein the second pair ofvideo cameras includes the first video camera and a third video camera.3. The system of claim 1, wherein the second pair of video camerasincludes a third video camera and a fourth video camera.
 4. The systemof claim 1, further comprising a head-mountable video display with aleft eye display and a right eye display to create the stereopsis usingthe first video feed and the second video feed, respectively.
 5. Thesystem of claim 1, further comprising an image processor configured toselectively modify one or more of the video feeds to provide astereoscopic viewable image having at least one adjusted visual propertyadapted for enhanced diagnostic or treatment visualization, wherein theadjusted visual property includes enhancement of a specific color orgroup of colors.
 6. The system of claim 5, wherein the specific color orgroup of colors is enhanced for diagnosing or treating cancers orlesions in the mouth.
 7. The system of claim 5, wherein the imageprocessor is to enhance the display of a colorant in the stereoscopicvideo image.
 8. The system of claim 1, further comprising a processorconfigured to calibrate and adjust a horizontal alignment of one or moreof the array of video cameras.
 9. The system of claim 8, wherein theprocessor provides for calibration with multiple users, and wherein thesystem calibrates to a first user in a first mode and a second user in asecond mode.
 10. The system of claim 8, wherein the horizontal alignmentis maintained during pan or tilt movements of one or more of the arrayof video cameras.
 11. The system of claim 1, wherein the tracking pointis associated with movement of the object.
 12. The system of claim 1,wherein a sensor is associated with the tracking device, and wherein alocation of the tracking point is based on a movement of the user. 13.The system of claim 1, further comprising digital or optical zoominglenses associated with the array of video cameras, the digital oroptical zooming lenses to provide a magnification of the stereoscopicvideo image.
 14. The system of claim 1, adapted for use in a dentalsetting, wherein the object is an intraoral cavity.